New Delhi: Stargazers in the capital will Saturday get a chance to observe celestial bodies in a sky free from light pollution as the city will turn off its lights to mark the Earth Hour 2012 beginning 8:30 p.m.

Science awareness organisation, SPACE (Science Popularization Association of Communicators and Educators) will set up telescopes at India Gate Saturday evening between 7:30 p.m. and 9:30 p.m. for people to observe how the sky looks in absence of light pollution.

SPACE will also conduct the Great Indian Star Count, a programme to measure light pollution. In this programme, people across the world look at the same constellation - `Orion` (The Hunter) and count the stars.

Orion is a constellation of seven main stars. But due to light pollution in big cities, some of the stars cannot be seen. The number of stars seen in different parts of the world, creates a global light pollution map.

The star count will be conducted before and during Earth Hour to point out the difference in the number of stars seen when the ambient lights are turned off.

Every year, during Earth Hour, lights at major monuments like India Gate or the Qutub Minar are turned off as a token step towards energy and environmental conservation.